Square Footage Calculator
Last updated: July 2026
Calculate rectangular area and estimated project cost.
Area
—
- Estimated project cost: —
- Area in square yards: —
On this page
Quick summary: Calculate rectangular area and estimated project cost. Enter the requested values, calculate, review the result, and compare more than one realistic scenario before making a decision.
Read the complete guide
What this calculator does
The Square Footage Calculator estimates the area of rectangular floors, walls, rooms, lots, or other surfaces from length and width measurements.
How to use the calculator step by step
Enter length and width using the same unit. If the page supports multiple sections, calculate each area separately and add them for irregular spaces.
How the calculation works
For a rectangle, area equals length multiplied by width. A room measuring 12 feet by 15 feet has an area of 180 square feet.
Worked example and scenario testing
Two rectangular sections measuring 10×12 feet and 6×8 feet have areas of 120 and 48 square feet, for a combined total of 168 square feet.
How to interpret your result
Square footage measures area, not perimeter or volume. It is commonly used for flooring, paint planning, property descriptions, and material estimation.
Accuracy, assumptions, and limitations
Irregular shapes, angled walls, stairs, openings, waste allowances, and measurement errors may require additional calculations.
Common mistakes to avoid
Do not multiply measurements expressed in different units without converting them first. Also do not confuse linear feet with square feet.
Privacy and browser-based calculations
Only dimensions are required. No property address or owner information needs to be entered.